Improvement in hoisting-jacks



W. A; GREE'NLEAP.

Hoisting-Jack.

No.196,117. Patented Oct. 16,1877.,

B Fig-.1 fig. 2.

c l i Cf G 0 'a o O @5- I a F 4:3 A. l AV l e l L Fz'g'- 4'.

ZINITED STATES.

PATENT OFFICE.

WILLIAM A. GREENLEAF, OF INDIANAPOLIS, INDIANA, ASSIGNOR OF ONE- HALFHIS RIGHT TO EWALD OVER, OF SAME PLACE.

IMPROVEMENT IN HOISTING-JACKS.

Specification forming part of Letters Patent No. 196,117, dated October16, 1877; application tiled May 1, 1877.

To all whom it may concern:

Be it known that I, WILLIAM A. GREEN- LEAF, residing in Indianapolis, inthe county of Marion and Stateof Indiana, have invented certainImprovements in Screw Hoisting- Jacks, of which the following is aspecification :v

This invention relates to the mode of operating the screw of screwhoisting jacks, or for other similar purposes where great force isrequired; and. it consists in the construction and arrangement of adriving-collar to the screw, that is furnished on its periphery withworm or tangent teeth;`f'and which is operated by a worm-screw, in theusual manner. The screw has a longitudinal groove and the collar afeather iitting into it, by which the screw is turned.

The object is to compound the screw-power` for raising great weight inan apparatus that is simple, compact, strong, and cheap in constructionand efficient in operation.

The invention further consists in the construction and arrangement of areversible and disconnectible ratchet-lever, that engages with a ratcheton the shaft of the worm-screw, by

which the latter may be operated when the crank cannot be used.

In the accompanying drawing, Figure l 1s an elevation, and Figfv 2 avertical section, of

screw; F, crank; Gr, ratchet-lever, the latter being shown in detail inFig. 4.

It will be seen that the mode of operating the screw B by means of theworm-collar D and screw E is convenient and efficient, as well asaffording a combination of the screw to eXert wonderful force. Theworm-collar 1) is kept in position by resting on the top of the lower.section of the case or stock A.

In the ratchet-lever the double reversible paWl e is pivoted at o, andthe outer end engages with the three-notched spring-holder s. When thispawl is set in either of the outer notches it will engage with theratchet-wheel r on that side, so as to run the screw B` up or down, asrequired. When the crank can be used, the ratchet-lever can bedisengaged from the ratchet-wheel r by setting its outer end in themiddle notch, when it will hang loosely on the shaft of screw E.

I do not make any claim, broadly, to operating the screw B byworm-gearing as a means of exerting great force, as this has been donein other similar devices, and is not new.

I claim as my inventionl. In combination with the nut C and groovedscrew B, the worm-collar D, fiunished withthe feather a, and operated bymeans ofthe wormscrew E, constructed and arranged and operatingsubstantially as set forth.

2. In combination with the nut C, screw I3, collar D, worm-screw E, theratchet-lever G, constructed, arranged, and operating substantially asset forth.

E WM. A. GREENLEAF.

Witnesses:

O. F. MAYIIEW, THOMAS J. VATER.

